A Node-RED Twitter-follower-flow

In my last blog post I did an introduction to “how use the starter kit for Node-RED on IBM Cloud” and in this new blog post I want to highlight the Node-RED Twitter-follower-flow I developed as an introduction to different topics I frequently face at hackathons. Here is the link to the “Twitter-follower-flow” GitHub project. Node-RED is very good for prototyping, that is the reason why it is often used in hackathons. If you are new to Node-RED and you start  to develop a Node-RED flow, you normally have following challenges:

  • How to …
    1. … define own REST endpoints to encapsulate an external API?
    2. … automate the authentication to that external API?
    3. … extract data from the external API?
    4. … customize data and CRUD with databases?

The Node-RED flow of that project has the objective to provide an (little advanced) introduction to the first three topics above. The CRUD (Create, Read, Update, Delete) topic is not covered here. Visit that CRUD example for more information.

  • The “Twitter-follower-flow” example …
    • … uses open technologies (Node-RED is a Project of the OpenJS foundation )
    • … creates no additional costs
    • … has following technical level:
      • Beginner to intermediate
      • Needs a basic knowledge of JavaScript and REST
    • … takes 30 – 45 min to setup the example from scratch
      1. Register on IBM Cloud
      2. Create a Node-RED instance on IBM Cloud
      3. Register at Twitter for a developer API Account
      4. Copy the existing Node-RED flow
      5. Configure the flow
      6. Run the flow

The YouTube video below gives you a 13 min more detailed introduction to the Twitter-follower-flow.

Continue reading

A short introduction of the Node-RED Starter kit on IBM Cloud for Hackathons

In that blog post I want to highlight the new way of the instantiation of a Node-RED application on  IBM Cloud with the Node-RED Starter kit. From my perspective Node-RED is a very helpful tool at hackathons. (just take a look in my blog post  How to prepare for a Hackathon with IBM Cloud?)

The Node-RED instantiation has changed and with the Node-RED Starter kit we can take the advantage of the capabilities of IBM Cloud to control the build, deployment and execution of the Node-RED application and we setup automatically all  development tools to work effectively in a small development team in our hackathon.

I want to provide a short walkthrough from my perspective and created a 13 min YouTube video in addition to that blog post.

Continue reading

CallForCode weather API in Node-RED

I notice there are some changes in the usage of the weather API. For that reason I created a very simple sample with Node-RED to access the weather forecast. The Node-RED flow implements the access to the weather API you can use during your CallForCode challenge.

Here is what you need to do, to get access to the weather API:

  1. Register on Welcome to The Weather Company API Platform Site Powering the best Weather Apps & Sites
  2. You will get a mail with the apikey
  3. Then you can use the documentation to access the APIweather-api-doc-2019

Please ensure you have following simple settings for your REST API request in place:

  1. The HTTP header must contain Accept-Encoding: gzip
    The reason for that is, that all responses of the weather API requests are compressed. The Supported encoding format is: gzip
  2. Use the parameter apiKey

The following picture shows a simple postman this request:

postman-weather

Inside the flow you have to replace the text YOUR_WEATHER_APIKEY  with the apiKey you got in your mail. Beware you have to install node-red-contrib-gzip in your Node-RED to use the sample. You can get the Node-RED flow from GitHub.

In the following gif you can see the usage of the flow:

node-red-weather

For a more detailed understanding, how the weather service can be used in real world UseCases, please visit that awesome blog post from Va Barbosa All for code the weather company and you .

I hope this was useful for you and let’s see what’s next?

Greetings,

Thomas

PS: By the way, you can use the IBM Cloud for free, if you simply create an IBM Lite account. Here you only need an e-mail address.

#IBMDeveloper, #CallForCode, #Node-RED, #WeatherAPI

 

 

Cors and Node-RED using a simple forwarding server

When you use Node-RED on IBM Cloud during hackathons you will notice REST calls in flows cannot be directly invoked from a web application. The reason for this is mostly that cors (cross-origin resource sharing) is not enabled for the Node-RED server. This blog post is a simple workaround for this problem.

By the way, you can use the IBM Cloud for free, if you simply create an IBM Lite account. Here you only need an e-mail address.

I developed this workaround to have full control and be very flexible during a hackathon, when using Node-RED for prototyping and building integrations to services and web-applications, without changing Node-RED settings or using cors browser enabler.

Continue reading